A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Kinetics and mechanisms for the isomerization of internucleosidic 3 '-O-P-CH2-5 ' and 3 '-O-P-CH(OH)-5 ' linkages to their 2 ',5 '-counterparts
Tekijät: Lonnberg T, Kralikova S, Rosenberg I, Lonnberg H
Kustantaja: INST ORGANIC CHEM AND BIOCHEM
Julkaisuvuosi: 2006
Lehti:: Collection of Czechoslovak Chemical Communications
Tietokannassa oleva lehden nimi: COLLECTION OF CZECHOSLOVAK CHEMICAL COMMUNICATIONS
Lehden akronyymi: COLLECT CZECH CHEM C
Vuosikerta: 71
Numero: 6
Aloitussivu: 859
Lopetussivu: 870
Sivujen määrä: 12
ISSN: 0010-0765
DOI: https://doi.org/10.1135/cccc20060859
Tiivistelmä
Isomerization of internucleosidic 3'-O-P-CH2-5' and 3'-O-P-CH(OH)-5' phosphonate linkages to their 2',5'-counterparts has been studied over a wide pH-range. The model compounds employed are phosphonate analogs of adenylyl-(3',5')-adenosine and adenylyl-(2',5')-adenosine having either adenosine ((R,S)-1, (R,S)-2) or 5'-deoxyadenosine (3, 4) bonded to the phosphorus atom through the C5'-atom. For comparative purposes, the hydrolytic stability of C5'-hydroxyphosphonate analogs derived from 2'-deoxyadenosine ((R,S)-5) has also been studied. In addition to the expected acid-catalyzed (pH < 3) and pH-independent reactions (pH 3-9), the diastereomeric C5'-hydroxyphosphonate analogs ((R,S)-1, (R,S)-2), but not their deoxy counterparts (3, 4), have been observed to undergo a hydroxide-ion-catalyzed isomerization around pH 11 (90 degrees C). Evidently a hydrogen bond between the dianionic phosphorane and the C5'-hydroxy group stabilize the phosphorane to such an extent that isomerization via kinetically invisible protonation to monoanion becomes possible. The mechanisms of the isomerization reactions taking place under various conditions are discussed.
Isomerization of internucleosidic 3'-O-P-CH2-5' and 3'-O-P-CH(OH)-5' phosphonate linkages to their 2',5'-counterparts has been studied over a wide pH-range. The model compounds employed are phosphonate analogs of adenylyl-(3',5')-adenosine and adenylyl-(2',5')-adenosine having either adenosine ((R,S)-1, (R,S)-2) or 5'-deoxyadenosine (3, 4) bonded to the phosphorus atom through the C5'-atom. For comparative purposes, the hydrolytic stability of C5'-hydroxyphosphonate analogs derived from 2'-deoxyadenosine ((R,S)-5) has also been studied. In addition to the expected acid-catalyzed (pH < 3) and pH-independent reactions (pH 3-9), the diastereomeric C5'-hydroxyphosphonate analogs ((R,S)-1, (R,S)-2), but not their deoxy counterparts (3, 4), have been observed to undergo a hydroxide-ion-catalyzed isomerization around pH 11 (90 degrees C). Evidently a hydrogen bond between the dianionic phosphorane and the C5'-hydroxy group stabilize the phosphorane to such an extent that isomerization via kinetically invisible protonation to monoanion becomes possible. The mechanisms of the isomerization reactions taking place under various conditions are discussed.
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